Rapid response of photorefraction in vanadium and magnesium co-doped lithium niobate

Abstract

Vanadium and magnesium co-doped LiNbO 3 (LN) crystals were grown, and their photorefractive properties were studied in the visible spectral region. At 488 nm the shortest response time of 80 ms was achieved for an LN crystal co-doped with 0.1 mol% V 2 O 5 and 6.0 mol% MgO, which is the more rapid than other reported doped LN crystals in the same wavelength region. The sensitivity of this crystal reaches 17 cm J −1 with an adequate diffraction efficiency of 4.0%. A schematic diagram for energy level is proposed and discussed. Through the analysis of defect structure and absorption spectra, we found that the change of the vanadium ions occupancy from Li sites to Nb sites is responsible for significant shortening the response time. The rapid response of vanadium and magnesium co-doped LN crystal can play an excellent role in the field of dynamic holography and practical holographic 3D-storage applications.

Enhancement of Photorefraction in Vanadium-Doped Lithium Niobate through Iron and Zirconium Co-Doping

“…To realize a nonvolatile readout, several methods have been developed so far, i.e., thermal fixing, electrical fixing, and two-step recording [14,22]. Though, up to now, there is good improvement in the response speed of the various doped LN crystals [23,24,25,26], much research is needed to get a practical fast responsive material with a high diffraction efficiency. Recently it was found that vanadium doping in LN elicited shortening of the response time [18,19,26,27].…”

Computer Simulation of the Incorporation of V2+, V3+, V4+, V5+ and Mo3+, Mo4+, Mo5+, Mo6+ Dopants in LiNbO3

“…Trivalent dopants: both V 3+ and Mo 3+ ions are predicted to self-compensate. Experimental data from [18] support V 3+ doping at the lithium site, as with V 2+ .…”

“…Divalent dopants: the calculations predict that, for V 2+ , self-compensation (simultaneous doping at lithium and niobium sites) and doping at the lithium site with lithium vacancy compensation are most likely. It is noted that V 2+ Li defects have been observed experimentally [18]. Trivalent dopants: both V 3+ and Mo 3+ ions are predicted to self-compensate.…”

“…V 4+ is predicted to self-compensate, while Mo 4+ is predicted to occupy a niobium site with oxygen vacancy charge compensation. Again, [18] suggests that V 4+ can dope at a lithium site.…”

“…Previous work on vanadium and molybdenum doped lithium niobate has included experimental studies of how its photorefractive properties are enhanced by doping with molybdenum ions [16,17] where it is suggested that the Mo 6+ ion dopes at the Nb 5+ site. Another study looks at LiNbO 3 co-doped with Mg and V, concluding that some of the vanadium dopes at the Nb site in the 5+ charge state, but that V 4+ Li , V 3+ Li and V 2+ Li defects are also observed [18]. Finally, another recent publication [19] has looked at the photorefractive response of Zn and Mo co-doped LiNbO 3 in the visible region, and concluded that the presence of Mo 6+ ions helps promote fast response and multi-wavelength holographic storage, which is attributed to their occupation of regular niobium sites in the lattice.…”